Export PDF with linked files doesn't save some of the links... ?

Export all to PDF "unsaves' 8 out of 12 documents, breaking the links that tie them together.
THis happened four times in a row yesterday, and again today. I save them all, keep them open, click export all to PDF, open the PDF and only a few are clickable. I look back at my open files in balsamiq and the same 8 documents have the "Changed" asterisk.
Am I doing soemthing wrong? How can I fix this? Is this the same problem as reported here: http://community.balsamiq.com/balsami...

I love Balsamiq and I don't want to go back to wireframing in fireworks, but i may have to if I can't save a clickable PDF.

Thanks!